The invention is directed to coating compositions made of plastisols and organosols which contain a polyaminoamide as an adhesive agent and to a process for improving the adhesion of these compositions to metallic bases. Plastisols are fluid dispersions of synthetic resins, especially polyvinylchloride (PVC), in plasticizers, which can contain additional fillers, dyes-pigments, and stabilizers.
Plastisols and organsols are frequently employed in the production of vehicles, for example, automobiles, e.g., as undercoat protective compositions, joint seals, or sound absorbents. As further areas of employment, there may be mentioned, e.g., the coating of pipes, textured materials and workpieces made of metal, as well as textile coatings.
They are applied by brushing, spraying, dipping, casting, or pressure processes.
After applying to the base customary PVC plastisols as a rule require gelling (fluxing) temperatures of 170.degree.-190.degree. C.
However, the trend, inter alia, to save energy, is continually to types of plastisols which will already guarantee sufficient gelation at about 140.degree. C.
Of great significance in industrial use is the adhesive strength of the plastisols and organosols to the base.
PVC plastisols and organosols which do not contain special additives especially cause problems because of their poor adhesion to the metallic bases.
Therefore, it is customary to add adhesion improving polymerizable compounds such as, e.g., trimethylolpropane trimethacrylate.
However, therewith there must also be considered the simultaneous disadvantage that one must not go below a specific temperature level since otherwise the polymerization reaction of the adhesive agent will not start.
Recently, there have also been used polyaminoamides which are also effective at lower temperatures. In spite of this, the plastisols processed at these temperatures only show an unsatisfactory adhesion to the different metallic bases.
The problem of the invention is to develop a coating composition made of a plastisol or organosol which also has sufficient adhesive power to metallic bases at low temperature.